Space Weather Message Code: ALTK06 Serial Number: 510 Issue Time: 2023 Feb 28 0255 UTC ALERT: Geomagnetic K-index of 6 Threshold Reached: 2023 Feb 28 0255 UTC Synoptic Period: 0000-0300 UTC Active Warning: Yes NOAA Scale: G2 – Moderate NOAA Space Weather Scale descriptions can be found at www.swpc.noaa.gov/noaa-scales-explanation Potential Impacts: Area of impact primarily poleward of 55 degrees Geomagnetic Latitude. Induced Currents – Power grid fluctuations can occur. High-latitude

Space Weather Message Code: ALTK05 Serial Number: 1439 Issue Time: 2023 Feb 28 0126 UTC ALERT: Geomagnetic K-index of 5 Threshold Reached: 2023 Feb 28 0119 UTC Synoptic Period: 0000-0300 UTC Active Warning: Yes NOAA Scale: G1 – Minor NOAA Space Weather Scale descriptions can be found at www.swpc.noaa.gov/noaa-scales-explanation Potential Impacts: Area of impact primarily poleward of 60 degrees Geomagnetic Latitude. Induced Currents – Weak power grid fluctuations can occur.

Space Weather Message Code: ALTK06 Serial Number: 509 Issue Time: 2023 Feb 27 2147 UTC ALERT: Geomagnetic K-index of 6 Threshold Reached: 2023 Feb 27 2146 UTC Synoptic Period: 2100-2400 UTC Active Warning: Yes NOAA Scale: G2 – Moderate NOAA Space Weather Scale descriptions can be found at www.swpc.noaa.gov/noaa-scales-explanation Potential Impacts: Area of impact primarily poleward of 55 degrees Geomagnetic Latitude. Induced Currents – Power grid fluctuations can occur. High-latitude

Space Weather Message Code: ALTK05 Serial Number: 1438 Issue Time: 2023 Feb 27 2124 UTC ALERT: Geomagnetic K-index of 5 Threshold Reached: 2023 Feb 27 2120 UTC Synoptic Period: 2100-2400 UTC Active Warning: Yes NOAA Scale: G1 – Minor NOAA Space Weather Scale descriptions can be found at www.swpc.noaa.gov/noaa-scales-explanation Potential Impacts: Area of impact primarily poleward of 60 degrees Geomagnetic Latitude. Induced Currents – Weak power grid fluctuations can occur.

Space Weather Message Code: WARK07 Serial Number: 86 Issue Time: 2023 Feb 27 1922 UTC WARNING: Geomagnetic K-index of 7 or greater expected Valid From: 2023 Feb 27 1922 UTC Valid To: 2023 Feb 27 2359 UTC Warning Condition: Onset NOAA Scale: G3 or greater – Strong to Extreme NOAA Space Weather Scale descriptions can be found at www.swpc.noaa.gov/noaa-scales-explanation Potential Impacts: Area of impact primarily poleward of 50 degrees Geomagnetic

Space Weather Message Code: ALTK06 Serial Number: 508 Issue Time: 2023 Feb 27 1907 UTC ALERT: Geomagnetic K-index of 6 Threshold Reached: 2023 Feb 27 1902 UTC Synoptic Period: 1800-2100 UTC Active Warning: Yes NOAA Scale: G2 – Moderate NOAA Space Weather Scale descriptions can be found at www.swpc.noaa.gov/noaa-scales-explanation Potential Impacts: Area of impact primarily poleward of 55 degrees Geomagnetic Latitude. Induced Currents – Power grid fluctuations can occur. High-latitude

Space Weather Message Code: ALTK05 Serial Number: 1437 Issue Time: 2023 Feb 27 1850 UTC ALERT: Geomagnetic K-index of 5 Threshold Reached: 2023 Feb 27 1848 UTC Synoptic Period: 1800-2100 UTC Active Warning: Yes NOAA Scale: G1 – Minor NOAA Space Weather Scale descriptions can be found at www.swpc.noaa.gov/noaa-scales-explanation Potential Impacts: Area of impact primarily poleward of 60 degrees Geomagnetic Latitude. Induced Currents – Weak power grid fluctuations can occur.

Space Weather Message Code: ALTK07 Serial Number: 123 Issue Time: 2023 Feb 27 1723 UTC ALERT: Geomagnetic K-index of 7 Threshold Reached: 2023 Feb 27 1721 UTC Synoptic Period: 1500-1800 UTC Active Warning: Yes NOAA Scale: G3 – Strong NOAA Space Weather Scale descriptions can be found at www.swpc.noaa.gov/noaa-scales-explanation Potential Impacts: Area of impact primarily poleward of 50 degrees Geomagnetic Latitude. Induced Currents – Power system voltage irregularities possible, false

Space Weather Message Code: ALTK06 Serial Number: 507 Issue Time: 2023 Feb 27 1604 UTC ALERT: Geomagnetic K-index of 6 Threshold Reached: 2023 Feb 27 1602 UTC Synoptic Period: 1500-1800 UTC Active Warning: Yes NOAA Scale: G2 – Moderate NOAA Space Weather Scale descriptions can be found at www.swpc.noaa.gov/noaa-scales-explanation Potential Impacts: Area of impact primarily poleward of 55 degrees Geomagnetic Latitude. Induced Currents – Power grid fluctuations can occur. High-latitude

Space Weather Message Code: ALTK05 Serial Number: 1436 Issue Time: 2023 Feb 27 1548 UTC ALERT: Geomagnetic K-index of 5 Threshold Reached: 2023 Feb 27 1546 UTC Synoptic Period: 1500-1800 UTC Active Warning: Yes NOAA Scale: G1 – Minor NOAA Space Weather Scale descriptions can be found at www.swpc.noaa.gov/noaa-scales-explanation Potential Impacts: Area of impact primarily poleward of 60 degrees Geomagnetic Latitude. Induced Currents – Weak power grid fluctuations can occur.